Process for producing multicolour photographic images

ABSTRACT

THE INVENTION DESCRIBES A PROCESS FOR THE MANUFACTURE OF COLOURED HALFTONE AND LINE-WORK PHOTOGRAPHIC IMAGES E.G. FOR COLOUR PROOFING. AN ELEMENT COMPRISING A TEMPORARY SUPPORT AND A LIGHTSENSITIVE LAYER, WHEREIN A COLOUR PIGMENT IS DISPERSED IN A PHOTO-SOLUBILIZABLE BINDER MATERIAL, IS TREATED AS FOLLOWS:   (A) EXPOSURE TO LIGHT THROUGH A COLOUR SEPARATION TRANSPARENCY, (B) DISSOLUTION OF EXPOSED PORTIONS, (C) PRESSING THE POSITIVE IMAGE FORMED ON A RECEPTOR SURFACE WETTED WITH A SOLVENT OR SWELLING AGENT FOR THE PHOTOSOLUBILIZABLE BINDER MATERIAL AND SEPARATION OF THE TEMPORARY SUPPORT, (D) DISSOLUTION OF TRANSFERRED BINDER MATERIAL WHEREBY A POSITIVE PIGMENT IMAGE REMAINS ON THE RECEPTOR.   IN THE CASE A MULTICOLOUR IMAGE IS DESIRED THE DIFFERENT STEPS ARE REPEATED WITH OTHER COLOUR SEPARATION TRANSPARENCIES AND OTHER PIGMENTED PHOTOSOLUBLIZABLE LAYERS ON TEMPORARY SUPPORTS, WHEREBY IN EACH STEP (C) THE NEW POSITIVE IMAGE IS TRANSFERRED TO THE RECEPTOR SURFACE IN REGISTER WITH THE PIGMENT IMAGE ALREADY PRESENT. WHEN THE TEMPORARY SUPPORTS ARE TRANSPARENT THE DIFFERENT COLOURED POSITIVE IMAGES FORMED ON THEM CAN ALSO BE COMBINED INTO REGISTER SO AS TO FORM AN OVERLY COLOUR IMAGE OF THE ORIGINAL.

United States Patent 01 dice 3,764,318 Patented Oct. 9, 1973 3,764,318 PROCESS FOR PRODUCING MULTICOLOUR PHOTOGRAPHIC IMAGES Urbain Leopold Laridon, Wilrijk, Belgium, assignor t Agfa-Gevaert N.V., Mortsel, Belgium No Drawing. Filed June 1, 197-1, Ser. No. 149,087 Claims priority, application Great Britain, June 2, 1970, 26,611/ 70 Int. Cl. G03c 7/00 U.S. Cl. 96-2 12 Claims ABSTRACT OF THE DISCLOSURE The invention describes a process for the manufacture of coloured halftone and line-work photographic images e.g. for colour proofing.

An element comprising a temporary support and a lightsensitive layer, wherein a colour pigment is dispersed in a photo-solubilizable binder material, is treated as follows:

(A) exposure to light through a colour separation transparency,

(B) dissolution of exposed portions,

(C) pressing the positive image formed on a receptor surface wetted with a solvent or swelling agent for the photosolubilizable binder material and separation of the temporary support,

(D) dissolution of transferred binder material whereby a positive pigment image remains on the receptor.

In the case a multicolour image is desired the different steps are repeated with other colour separation transparencies and other pigmented photosolubilizable layers on temporary supports, whereby in each step (C) the new positive image is transferred to the receptor surface in register with the pigment image already present.

When the temporary supports are transparent the different coloured positive images formed on them can also be combined into register so as to form an overlay colour image of the original.

This invention relates to the production of photographic colour separation images which can serve as colour proofs.

This invention relates more particularly, but not exclusively to a process for producing halftone and line-work plural or multi-colour photographic images by forming partial images in register on a receptor surface, and to photographic materials used therefor.

The term register as used herein is intended to cover the correct relative placement of two or more single colour images, e.g., on a receptor, in such a way that a perfect, well defined plural or multi-colour image is formed. Registration can be accomplished visually, e.g., through the use of register marks on the separation colour transparencies or on such transparencies and a receptor, or by use of prepunched transparencies that are mounted on appropriate locating pins during exposure, and during transfer of the colour separation images to a receptor sheet if that transfer is effected.

The production of halftone and line-Work, plural or multi-colour images is of interest in the field of design, e.g., in the production of colour patterns, colour wiring and circuit diagrams, cartography, colour prOOfing and in the production of transparencies for dia and overheadprojection. Especially in the graphic arts there is a great need for a simple and fast technique producing colour proofs of high quality and reproducibility. Indeed, in the graphic arts it is desirable to produce four or more colour proofs to assist a colour etcher in correcting a set of colour printers prior to using them to produce colour plates and also to reproduce the colour quality that will be obtained during the printing process.

Therefore, it is an object of this invention to provide a new and practical process for producing colour proofing images.

According to the present invention, a colour separation image useful for colour proofing is produced from a coloured original on an element comprising a support carrying a light-sensitive layer containing a colour pigment or dye in a photo-solubilizable binder material, by (A) exposing the photo-solubilizable layer to actinic light through a colour separation transparency which records the distribution in the original of the colour to be represented by said pigment or dye; and (B) dissolving away the exposed portions of such layer thereby leaving a coloured positive image of said colour separation transparency on the said support. For producing a plural or multi-colour image, e.g., a coloured halftone or line-work image from a coloured original, the foregoing steps are repeated one or more times, using in the or each case a light-sensitive element with a light-sensitive layer of a different colour and a different colour separation transparency which records the distribution of the appertaining colour in the original, and the required plural or multicolour image is produced by combining the different coloured positive images of the different color separation transparencies. The coloured colour separation images thus produced can be brought into register one on another so as to form an overlay colour image of the original. In this case the supports of the light-sensitive elements should preferably be transparent. As an alternative, if the light-sensitive elements are suitably constituted so that the coloured positive images formed therein can be transferred from their supports to a receptor surface, the pluralor multi-colour image can be produced by transferring the individual coloured positive separation images in register onto such surface. The most preferred embodiments of the present invention make use of this transfer procedure. The light-sensitive layers of the different light-sensitive elements, and the receptor surface, are preferably constituted so that after transferring each coloured positive separation image to such surface, the photo-solubilizable binder material can be removed by a solvent while leaving a positive pigment or dye image on the receptor surface.

The present invention, according to a preferred aspect thereof, accordingly comprises a process for the production of a plural or multi-colour photographic image of an original wherein a colour separation image is produced on a light-sensitive element by a process comprising steps (A) and (B) as hereinbefore defined using a light-sensitive element in which the light-sensitive layer is borne by a temporary support, whereafter the following further steps are performed: (C) the positive image is transferred by adhesion to a receptor surface in the presence of a solvent or swelling agent for the photosolubilizable binder material; (D) the receptor is washed with a solvent for such binder material causing removal of such material while leaving the positive pigment or dye image on the receptor surface; and (E) a different coloured positive separation image or each of two or more different coloured positive separation images which has or have been formed from the original on different light-sensitive elements by performance of steps corresponding with (A) and (B) is likewise transferred to the receptor surface in register with the positive image or images already present, the or each said further transfer being followed by washing the receptor with a solvent to remove photo-solubilizable binder transferred to the receptor in that transfer step. Advantageously the receptor surface is wetted with a solvent or swelling agent for the photo-solubilizable binder material prior to transfer of a positive image thereto.

By way of modification, it is possible in any process according to the invention as hereinbefore defined to employ a light-sensitive element which contains, in lieu of a colour pigment or dye, a colour-forming compound which can be converted to a coloured compound by treatment with an appropriate reactant, e.g., after dissolving away the exposed portions of the light-sensitive layer or even after transfer of the positive (latent) image to a receptor.

In a preferred embodiment of the present invention the photosolubilizable binder material is formed by a mixture of an alkali-soluble polymer and a naphthoquinone diazide or a bisphenol modified to give a bis(o-quinone-diazide), such as described in the United Kingdom patent specifications 1,116,674 and 1,116,737 respectively.

Suitable alkali-soluble polymers are the copolymers of unsaturated carboxylic acids, such as acrylic acid, methacrylic acid, crotonic acid, maleic acid, fumaric acid, itaconic acid, and citraconic acid. If the copolymer comprises an unsaturated dicarboxylic acid, the half-esters and half-amides thereof may be used too. These unsaturated carboxylic acids are copolymerized with ethylenically unsaturated compounds that are substantially insoluble in alkaline medium and that are present in the copolymer in such a proportion that the copolymer itself remains soluble in alkaline medium. Ethylenically unsaturated compounds that may be copolymerized include styrene and its derivatives, vinyl chloride, vinylidene chloride, vinyl esters such as vinyl acetate, acrylic acid esters, methacrylic acid esters, acrylonitrile, methacrylonitrile, etc.

Preferred alkali-soluble polymers, however, are the socalled novolaks. According to British Standard 1755-1951 these are soluble, fusible, synthetic resins produced from a phenol and an aldehyde, having no reactive groups (i.e. methylol groups) in the molecule and therefore incapable of condensing with other novolak molecules on heating without the addition of hardening agents.

Suitable naphthoquinone-diazides are naphthoquinone- 1,2-diazide(2)4-sulphofluoride and naphthoquinone-1,2- diazide(2)-5-sulfofluoride. In the United Kingdom patent specification 1,116,737 are listed bis(o-quinone-diazides) deriving from the modification of bisphenols. The most interesting of these bis (o-quinonediazides) are bis(6-diazo-2,4-cyclohexadien-4-yl-1-one)-phenylmethane,

2,2-bis 2-methyl-6-diazo-2,4-cyclohexadien-4-yl- 1- one) propane,

bis (2-bromo-6-diazo-2,4-cyc1ohexadien-4-,'ll-one sulphone and 1, l-bis (Z-methyl-6-diazo-2,4-cyclohexadien-4-yl- 1- one) cyclohexane.

The amount of alkali-soluble resin added to the lightsensitive quinone-diazides may vary within wide limits. Preferably, however, at least 4 parts by weight of alkalisoluble resin are present for every part by Weight of lightsensitive compound or compounds containing quinonediazide groups.

In a further preferred embodiment the photosolubilizable binder material is formed by a mixture of an alkalisoluble polymer and a compound containing a diazosulphone group such as described in the Belgian patent specification 740,597.

The alkali-soluble polymers used are the same as those described above. A large group of compounds containing a diazosulphone group is given in the Belgian patent specification 740,597. Most interesting are (p-acetamido-phenylsulphonyl) p-diethyl-aminophenyl) -diimide,

(p-tolylsulphonyl) (p-anilinophenyl) -diimide,

( p-tolylsulphonyl) (p-dimethylaminophenyl) -diimide,

( p-tolylsulphonyl) (p-diethylaminophenyl) -diimide, and

(p-tolylsulphonyl) (4diethylamino-2-methyl-phenyl) diimide.

As in the case of naphthoquinone-diazides and of the bis(o-quinone-diazides) the amount of alkali-soluble resin added to the light-sensitive compound containing a diazosulphone group may vary within wide limits. Preferably, however, at least 4 parts by Weight of alkali-soluble resin are present for each part by Weight of diazosulphone.

In another preferred embodiment of the invention the photosolubilizable binder material is formed from a mixture of an alkali-soluble resin, such as a novolak, and a compound containing a diazeomethane group corresponding to the formula:

wherein R and R (same or diiferent) represent substituted or unsubstituted aliphatic, aromatic, or heterocyclic groups. These compounds have been described in the published Dutch patent application 68/12645. Very interesting are the compounds that contain a diazomethane group wherein R is a dialkylaminophenyl group, e.g. (p tolylsulphonyl)-(p dimethylamino benzoyl)-diazo methane.

A photosolubilizable element is made by applying solutions of photosolubilizable mixtures of alkali-soluble polymer and of light-sensitive compounds as layers on temporary supports. The light-sensitive coating composition may also compirse stabilizers, plasticizers, extenders, dyes and also minor amounts of additives increasing the lightsensitivity of the compositions.

The light-sensitive coating composition formed is applied to the temporary support by spray, brush, roller, doctor blade, air brush, or wiping techniques, in order to leave thereon after evaporation of the solvent or solvent mixture a coating having a thickness of 0.5 to 20 preferably of l to 5 1.. The light-sensitive coating is then ready for exposure to actinic light rays. Suitable light sources include carbon arcs, xenon lamps, mercury vapour lamps, fluorescent lamps, argon glow lamps, photographic flood lamps, and tungsten lamps.

In the case of proofs for graphic art work, each lightsensitive layer will contain a colourant, i.e. a pigment or a. dye, that should be of such a class that when the layer is transferred to the receptor, its colour value will approximate the colour value that will be produced by the printing ink to be used.

For the reproduction of e.g. a three-colour original, each of the three-dye-containing photosolubilizable elements is exposed through an appropriate colour separation photographic positive transparency. The exposed portions of the photo-solubilizable layer become soluble in alkaline medium, probably through photolytic transformation of the light-sensitive compounds so that the development or removal of the coating in the exposed areas can be effected by means of an aqueous composition, preferably by means of an alkaline aqueous solution rapidly dissolving the image-wise formed decomposition products. A convenient alkaline developer is an aqueous solution of a phosphate of an alkaline metal e.g. sodium phosphate, or an aqueous solution of sodium hydroxide or a mixture of both.

The result of this development is a positive pigmented image from the original colour separation transparency on the temporary support.

Before use the receptor surface is wetted with a solvent or swelling agent for the photosolubilizable binder material. Immediately thereafter, temporary support and receptor surface are pressed together with the pigmented image in between, e.g. by means of 2 rollers. As a result of the action of the solvent or the swelling agent on the pigmented image layer, the latter becomes softened on its surface and attaches itselves to the receptor surface, so that when pulling away the temporary support, the pigmented image formed by the pigmented photosolubilizable binder material remains attached to the receptor surface.

In a following process step the receptor bearing a pig mented image formed of still light-sensitive photosolubilizable binder material is washed with a solvent for the photosolubilizable binder, that is washed away thereby, thus surprisingly leaving an exact pigment replica of the pigmented image on the receptor surface.

A second colour separation transparency is used to expose on a temporary support another photosolubilizable layer containing a suitable pigment or dye. Here also the exposed portions of the layer are dissolved away in aqueous alkaline medium so that a pigmented positive image from the second colour separation transparency remains on the temporary support. As in the case of the first pigmented image, the receptor surface already carrying this first pigment image is Wetted with a solvent or swelling agent for the photosolubilizable binder material and immediately thereafter the second temporary support is pressed thereto, with the pigmented image between them. Care must be taken that the second pigmented image is applied to the receptor surface in exact register with the already present first pigment image. Next, the second temporary support is pulled away.

Thereafter the further process steps are carried out to dissolve the still light-sensitive photosolubilizable binder material leaving a new pigment image in register with the first one.

Additional pigment images of further colour separation transparencies can be printed in the same way on the receptor surface.

Various dyes, pigments, and colour-forming components can be incorporated into the photosolubilizable binder material. The dyes have to be resistant to diffusion and chemically inert as much as possible in the processing and washing liquids. When used in colour proofing they have to match with the absorption spectrum of the standard inks as close as possible. Particulars about standard colour inks can be found in H. M. CartwrightIlford Graphic Arts Manual (1962) vol. I-pages 502 to 504.

There exist cold and warm colour standards. Cold colour tones are standardized in the USA. in the GATF- Color Charts and in Germany in the German Standards DIN 16508 and 16509. Warm colour tones are standardized in e.g. the German Standard DIN 16538.

The cold colour standards are characterized by the use of fairly pure magenta pigments, mostly insolubilized Rhodamine and Phloxine-dyes, which have a very low side-absorption in the blue region of the spectrum.

The warm colour standards are characterized by the use of insoluble azo dyestufis. Such dyestuffs are more resistant to solvents e.g. alcohol than the Rhodamines and Phloxines, but they show a much higher side-absorption in the blue region of the spectrum.

It has been found experimentally that pigments that are very poorly soluble or insoluble in water and organic liquids of the alcohol or polyhydric alcohol type e.g. glycerol, fulfill the requirements of resistance to diffusion. Pigment dyes that are applied from an aqueous dispersion are used preferably, though the use of substantive dyes that are chemically linked to a colloid or polymer is not excluded.

For colour proofing purposes the photosolubilizable binder material contains pigments in such a high concentration that the optical density in the wavelength range of maximum absorption is at least 0.35.

Apart from the use of dyes, the absorption spectrum of which has to satisfy particular requirements for colour proofing, all colours are considered e.g. cyan, light-cyan, magenta, warm magenta, black, yellow, green, brown, orange, red, white blue as Well as metallic colours such as pale gold, rich gold, copper, and silver. In other words the term colour in the present invention is meant to encompass all pure and mixed colours as well as blackand-white.

The proper dye can be chosen very easily by the average worker skilled in the art by making a series of tests. Carbon black is generally used as a black pigment.

The adhering power of the photosolubilizable coating to its temporary support, preferably a flexible one, has to be adjusted in such a way that an easy stripping off from the temporary support is possible after pressing the temporary support and the receptor together with the positive image between them. A relatively hydrophobic temporary support e.g. an unsubbed cellulose triacetatc sheet, a polystyrene sheet, or a sheet of co(vinyl acetate/ vinyl chloride) and a receptor having a hydrophilic surface e.g. a subbed polyethylene terephthalate support can be used therefor, e.g. a hydrohobic support subbed as described in the Belgian patent specification 721,469. According to a preferred embodiment the photosolubilizable coating is composed in such a way that its adherence to the temporary support in wet state is weaker than in dry state. This can be attained by the addition of hygroscopic agents e.g. a water-soluble organic hygroscopic compound e.g. glycerol and the use of wetting agents and plasticizing agents.

The receptor may be rigid or flexible and should only have a good adherence in wet as well as in dry state to the transferable photosolubilizable coating by nature or as a result of (a) subbing layer(s) applied thereto.

Depending on the use of the multicolour print the receptor support is transparent or opaque. So, it is possible to use metal layers or sheets, glass, ceramics, resin supports, and paper impermeabilized for the processing and washing liquids.

Resin supports having a high mechanical strength, a very low water-absorption, and consequently a high dimensional stability in dry and wet state can be made of a linear polyester e.g. polyethylene terephthalate. Good results as to the dimensional stability are attained with aluminium sheets sandwiched between two high wetstrength paper sheets, but though this material is rather expensive.

Receptor resin supports can be made opaque by coating them with a matted subbing layer or by matting or colouring them in the mass. The matting can be effected by pigments known in the art e.g. titanium dioxide, zinc oxide, and barium sulphate.

Hydrophobic resin supports to be used as receptor according to the present invention can be coated with one or more subbing layers. Preferred subbing layers for use on a receptor hydrophobic resin support e.g. a polyethylene terephthalate support, are described in the Belgiant patent specification 721,469. In the said specification a sheet material is claimed, which consecutively comprises a hydrophobic film support, a layer (A) that directly adheres to the said hydrophobic film support and comprises a copolymer formed from 45 to 99.5% by Weight of at least one of the chlorine-containing monomers vinylidene chloride and vinyl chloride, from 0.5 to 10% by Weight of an ethylenically unsaturated hydrophilic monomer, and from 0 to 54.5% by weight of at least one other copolymerisable ethylenically unsaturated monomer; and a layer (B) comprising in a weight ratio of 1:5 to 1:05 a mixture of gelatin and a copolymer of 30 to 70% by weight of butadiene with at least one copolymerizable ethylenically unsaturated monomer.

The different colour separation transparencies used are made according to processes known in the art. The multicolour original is photographed two or more times through different colour filters to produce a separate transparency for each filter. Each transparency will print only the colours that its filter allows to pass. Although the separation transparencies usually will print yellow, cyan, magenta, and black, others can be used such as pink, grey, or dark-blue printers.

When the exposed parts of the image-wise exposed photo-solubilizable layer on the temporary support are colurs that its filter allows to pass. Although the separawashed away parts. The pigment of dye must not however be removed from the transferred composition when the receptor surface is washed. In carrying out the invention we use a temporary support the surface of which is rather hydrophobic whereas the receptor which is used has a surface which is rather hydrophilic or hydrophilized by the presence of (a) suitable subbing layer(s). Further, the receptor surface is wetted prior to the transfer, with a solvent or a swelling agent for the photosolubilizable layer, so that the dye can penetrate in the pores of the receptor surface and remain there, after the light-sensitive layer has been washed away. A permanent pigment image has formed then.

EXAMPLE 1 Formation of colour images with naphthoquinone-l,2-

diazide(2)-5-sulphofluoride (A) Composition of the photosolubilizable layers (1) Cyan layer: In a mixture of 17.5 ml. of ethylene glycol monomethyl ether and 17.5 ml. of acetone, 1.4 g. of naphthoquinone 1,2 diazide(2)-5-sulphofiuoride and 5.6 g. of Alnovol 429 K (trade name for a novolak sold by Chemische Werke Albert) were dissolved. The naphthoquinone-diazide was prepared as described in Example 1 of United Kingdom patent specification 1,116,674.

The resulting solution was then admixed with:

Heliogenblau B Colanyl Teig (C.I. 74,160) (a cyan pigment dispersion marketed by Badische Anilinund Soda-Fabrik AG, Ludwigshafen (Rhine, Germany) g 1.2 Ethylene glycol monornethyl ether ml Methyl glycol acetate ml The resulting mixture was then stirred for 10 min. at 30 C. by means of a high speed stirrer (20,000 r.p.m.). The emulsion obtained was filtered through nylon cloth and applied to a temporary support of biaxially oriented polyethylene terephthalate having a thickness of approximatively 0.1 mm. The layer was coated in such a way, that to 30 g. of emulsion covered 1 sq. m. The lightsensitive layer was dried in a drying oven at 5060 C.

(2) Yellow layer: This layer was made in the same way as in (1). The cyan paste, however, was replaced by 1.5 g. of Yellow pigment 16 (Cl. 20,040) (Permanent Gelb NCG Colanyl Teig-trade name of Farbwerke Hoechst AG, Germany).

(3) Magenta layer: In the coating composition of (l) the cyan paste was replaced by 1.8 g. of Permanent Carmin FBB Colanyl Teig (C.I.) 11,000 (trade name of Farbwerket Hoechst, Germany).

(4) Black layer: In a coating composition of (1) the cyan paste was replaced by 2 g. of the black paste: Russdispersion P 130 (trade name of Deutsche Goldund Silber-Scheideanstalt, Germany).

(B) Composition of the receptor support Both sides of a biaxially oriented polyethylene terephthalate film having a thickness of 180g. were coated with the following composition at -30 C. at a ratio of 1.6 g./sq m.;

Copolymer of vinylidene chloride, N-tert.-butylacrylamide, n-butylacrylate, and N-vi-nyl pyrrolidone (ratio by weight: 70:23:3:4) g 5.5 Methylene chloride ml 65 1,2-dichloroethane ml 35 The resulting layer was coated with a mixture prepared as follows:

1350 g. of titanium dioxide (average particle size: 0.11 were dispersed in 5 l. of Water containing 25 ml. of Dequest 2006 (trade name of Monsanto Chemical Company, St. Louis, Mo., USA.) for a dispersing agent corresponding to the following structural formula:

The dispersion was stirred rapidly for 10 min. at a temperature of 5 to 15 C. and then heated to 35 C., at which temperature 400 m1. of a 10% by weight aqueous solution of gelatin were added, while continuing the rapid stirring. Subsequently, the following composition was added whilst stirring slowly to avoid scumming:

A 10% by weight aqueous solution of gelatin 1800 Water 130 20% by weight latex of the copolymer of butadiene and methyl methacrylate (ratio by weight 50:50) 2500 10% by weight aqueous solution of the sodium salt of oleylmethyltauride 37.5

Ethylene chlorohydrin 500 The coating was carried out at such a ratio that upon drying a layer having a thickness of 5a was obtained.

(C) Exposure of the photosolubilizable layers The cyan and magenta light-sensitive layers were exposed for 5 min. through their corresponding colour separation transparency in a vacuum frame at a distance of 15 cm. by means of an watt high pressure mercury vapour lamp. The yellow and black layers were exposed in the same way, but for 10 min.

(D) Development of the exposed layers The exposed layers could be developed in several ways:

(1) The developer is a 10% aqueous solution of sodium phosphate. The exposed layers were immersed for 2 min. in the developing bath, whereupon the exposed portions were washed away by rubbing gently with a sponge or with a plug of wadding. The resulting diapositive image was then removed from the bath, rinsed carefully with water and dried in a hot air-stream.

(2) The developer is a 0.5% aqueous solution of sodium hydroxide. The exposed layers were immersed for 1 min. in this developing bath, where-upon the exposed portions were washed away with a sponge or a plug of wadding as described in paragraph (1). Subsequently, the resulting image was rinsed and dried as described under (1). In this manner four coloured separation diapositives were obtained.

(E) Formation of pigment image by transfer to the receptor support The receptor support was immersed for 30 sec. to 1 min. in a mixture of ethanol and water (80:20 by volurne) or in a methanol bath. By means of a pair of rubber rollers the temporary support carrying the cyan pigmented image was pressed against the receptor surface with the cyan pigmented image between them. After a contact period of 30 sec. the temporary support was peeled apart. A positive print of the cyan pigmented separation diapositive remained on the receptor support,

The receptor support was then immersed again for 30 sec. to 1 min. in a mixture of ethanol and water (80:20 by volume) or in a methanol bath. The non-exposed quinone-diazide and the novolak were extracted thereby, so that only a cyan pigment image remained on the receptor surface. The receptor surface was dried with a hot air-stream.

The same process was repeated with the yellow, magenta, and black separation di'apositives, which were transferred each time in register to the same receptor support. Finally, a multicoloured image was obtained on the receptor. This image was an exact reproduction of the original, from which the difierent colour separation transparencies had been made.

The different pigmented images on the temporary supports could also be registered easily in overlay. In this way there was also obtained a sharp colour reproduction of the original.

EXAMPLE 2 Formation of colour images with compounds containing a diazosulphone group (A) Composition of the photosolubilizable layers 1) Cyan layer: In a mixture of 17.5 ml. of ethylene glycol monomethyl ether and 17.5 ml. of acetone 0.7 g. of (p-tolylsulphonyl)-(p-diethylaminophenyl) diimide and 6.3 g. of Alnovol 429 K (novolak of Chemische Werke Albert) were dissolved. The solution was then admixed with:

A pigment dispersion Luconylblau LBGO (trade name of Badische Anilin- & Soda-Fabrik, Ludwigshafen (Rhine, Germany) g 1.2 Ethylene glycol monomethyl ether ml Methyl glycol acetate ml The resulting mixture was treated in the same way as described in Example 1(A)(1) and coated also on a biaxi-ally oriented polyethylene terephthalate film.

(2) Yellow layer: This layer was composed in the same way as the cyan layer. The cyan paste, however, was replaced by 1.5 g. of pigment dispersion Imperongelb K-GG (high concentration) (trade name of Farbwerke Hoechst, Germany).

(3) Magenta layer: This layer was formed in the same way as in paragraph (1) with the difference, however, that the cyan paste was replaced by 1.8 g. of pigment dispersion Permanent Carmin FBB Colanyl Teig (C.I. 11,000) of Farbwerke Hoechst, Germany).

(4) Black layer: This layer was formed in the same way as described in paragraph (1) with the difference, that the cyan paste was replaced by 2.5 g. of Russdispersion P 130 of Deutsche Goldand Silberscheideanstalt.

(B) Exposure of the photosolubilizable layers The exposure was performed in the same way as described in Example 1(C).

(C) Developement of the exposed layers The exposed layers were immersed in a 0.7% aqueous solution of sodium hydroxide. After 1 min. the exposed portions were washed away by rubbing gently with a sponge or a plug of wadding. The resulting diapositive was removed from the bath, rinsed with water, and dried in a hot air-stream.

(D) Formation of pigment image by transfer to the receptor support The same receptor film as in Example 1(B) was used here. The process of Example 1(E) was repeated. An exact reproduction of the original coloured image was obtained.

10 EXAMPLE 3 Formation of colour images with compounds containing a diazomethane group (A) Composition of the light-sensitive layers 1) Cyan layer: 6.3 g. of novolak and 0.7 g. of (p-tolylsul honyl (p-dimethylaminobenzoyl) -diazomethane Were dissolved in a mixture of 17.5 ml. of ethylene glycol monomethyl ether and 17.5 ml. of acetone. To the resulting solution a mixture of 1.2 g. of cyan paste Luconylblau LBGO (trade name of Badische Anlin- & Soda- Fabrik) in 10 ml. of ethylene glycol monomethyl ether and 15 ml. of methyl glycol acetate was added.

The mixture was stirred for 10 min. with a high speed stirrer with 20,000 r.p.m. Subsequently, the light-sensitive emulsion was filtered through a nylon cloth and coated at a ratio of 20-30 g. of emulsion per sq.m. on a biaxially stretched polyethylene terephthalate film support. The light-sensitive film was dried at 5060 C.

(2) Yellow layer: The process of (1) was repeated, with the difference, that the cyan paste was replaced by 1.5 g. of Imperongelb K-GG (high concentrated) (trade name of Farbwerke Hoechst, Germany).

(3) Magenta layer: The process of (l) was repeated, with the difference, however, that the cyan paste was replaced by 1.8 g. of Permanent Carmin FBB Colanyl Teig (C.I. 11,000) (trade name of Farbwerke Hoechst).

(4) Black layer: The process described in paragraph (1) was repeated, with the difference, however, that the cyan paste was replaced by 2.5 g. of Russdispersion P (trade name of Deutsche Goldund Silberscheideanstalt).

(B) Exposure of the light-sensitive layers In the same way as described in Example 1(C).

(C) Development of the exposed layer In the same way as described in Example 1(D).

(D) Formation of the colour image by transfer to a receptor surface Same process as described in Example 1(E). A finished sharp coloured image of the original was obtained.

EXAMPLE 4 Formation of colour images with bisphenols modified to give a bis(o-quinonediazide) In example 2(A) 1) (p-tolylsulphonyl)-(p-diethylaminophenyl)-diimide was replaced by 0.7 g .of bis(2- bromo--diazo 2,4 cyclohexadien 4 yl 1 on)- sulphone. The further treatments were as described in Example 2. For the development of the exposed layer a developing bath was used, which contained 50 g. of sodium phosphate and 0.5 g. of sodium hydroxide per liter of water.

A sharp reproduction of the original colour image was obtained.

We claim:

1. Process for the production of a colored photographic image by exposure to actinic light of a material comprising a relatively hydrophobic temporary support carrying a light-sensitive layer formed from a substantially waterinsoluble color pigment dispersed in a photosolubilizable binder comprising a mixture of an alkali-soluble polymer and a quinone diazide, diazosulfone, or diazomethane compound, said process comprising the steps of:

(A) exposing said photosolubilizable layer to actinic light through a color separation transparency;

(B) dissolving away the exposed portions of the layer in alkaline medium thereby leaving a pigmented posi tive image of the original color separation transparency on the temporary support;

(C) transferring the resultant positive image to a relatively hydrophilic receptor surface by pressing the temporary support carrying the positive image against a receptor surface previously wetted with a solvent or swelling agent for said photosolubilizable binder, and separating the temporary support from the re- 1 1 ceptor surface, the pigmented image formed by said pigmented photosolubilizable binder remaining attached to the receptor surface; and

(D) washing the receptor surface and the pigmented image with a solvent for said photosolubilizable binder to dissolve away said binder, thereby leaving a residual positive pigment image on the receptor surface.

2. A process for producing a multi-color image from a colored original according to claim 1 wherein steps (A)- (D) are repeated one or more times, using in each case a light-sensitive element with a light-sensitive layer of a different color and a dilferent color separation transparency which records the distribution of the corresponding color in the original, and wherein a multi-color image is produced by combining the different colored positive images of the different color separation transparencies.

3. A process according to claim 1, wherein the said different coloured positive images are combined by bringing the said images, on their supports, into registration with each other.

4. A process according to claim 2, wherein the said different coloured positive images are combined by transferring them in registration onto a receptor surface.

5. A process according to claim 4, wherein after transferring each coloured positive separation image to said receptor surface, the photo-solubilizable binder material transferred in each such transfer step is removed by said solvent while leaving the positive pigment on the receptor surface.

6. Process according to claim 1, wherein said binder is a mixture of a novolak resin and a naphthoquinone-1,2- diazide (2)-[4] sulphofiuoride.

7. Process according to claim 1, wherein said binder is a mixture of a novolak resin and bis-(2-bromo-6-diazo- 2,4-cyclohexadien-4-yl l-on) sulphone.

8. Process according to claim 1, wherein said binder is a mixture of a novolak resin and (p-tolylsulphonyl)-(pdiethylaminophenyl) diimide.

9. Process according to claim 1, wherein said binder is a mixture of a novolak resin and (4-5-olylsulphonyl)-(4- dimethylaminobenzoyl)-diazomethane.

10. Process according to claim 1, wherein the exposed portions of said photo-solubilizable layer are washed away with an aqueous solution of sodium phosphate or of sodium hydroxide.

11. Process according to claim 10, wherein transfer is elfected onto a receptor surface wetted with methanol or a mixture of ethanol and water.

12. Process according to claim 1, wherein the unexposed photosolubilizable binder is washed away from said receptor surface with a mixture of ethanol and water.

References Cited UNITED STATES PATENTS 3,445,177 5/1969 McKesson 869 3,103,404 9/1963 Salvin et al. 869 2,637,621 6/1953 Auer 869 2,189,807 2/1940 Lenher et al 869 2,689,162 8/1954 Lee et al. 869 3,634,087 1/1972 Houle et al. 9614 2,787,543 4/1957 Murray et al. 9614 2,508,213 5/1950 Ball 9614 3,481,736 12/1969 Ruff 9628 3,525,615 8/1970 Chambers 9628 3,563,742 2/1971 Phlipot et al 9628 3,674,479 7/1972 Kampfer et al 9628 FOREIGN PATENTS 1,116,737 1968 England. 1,116,674 1968 England.

NORMAN G. TORCHIN, Primary Examiner E. C. KIMLIN, Assistant Examiner US. Cl. X.R.

UNITED STATES PATENT OFFICE CERTIFICATE OF CORECTION Patent No, 3 r r Dated October 9 1973 Urbain Leopold LARIDON Inventor(s) It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:

Column ll, Claim 3 line 18, change "claim 1" to claim 2- Column ll, Claim 6 line 33, cancel [4] Column 12 Claim 9 line 1, change (4-5-olylsi1lphonyl) to (uigolylsulphonyl) Signed and sealed this 19th day of March l97) I (SEAL) Attest:

EDWARD M.FLETGHER, JR. 0. MARSHALL DANN Attesting Officer Commissioner of Patents 

